Conventional chewing gum products are not “environmentally-friendly.” They can maintain stickiness during and after chewing and adhere to the ground (as well as any other surface with which the gum product may come into contact) if care is not used with regard to disposal of the gum product. The stickiness of such conventional chewing gum products results, in large part, from the use of elastomer solvents (i.e., resins) and other “tacky” ingredients (such as wax) during the manufacturing process. In particular, conventional chewing gums manufactured using elastomer solvents exhibit a continuous or substantially continuous phase when chewed. As the continuous phase is characterized by an amorphous elastomer matrix containing sticky elastomer solvents, the gum bolus that results upon chewing also is sticky.
Many elastomers, and particularly high molecular weight elastomers (e.g. 200,000 mw or greater), used in chewing gum compositions are usually solid at room temperature. They are usually purchased as blocks of solid material and generally require softening using solvents to be useful in chewing gum compositions. Softening elastomers in the absence of elastomer solvents is difficult, because the solid elastomer must still be processed into a continuous homogeneous and flowable mass to be useful in chewing gum compositions.
Although gum products that are manufactured without the use of elastomer solvents and/or other “tacky” ingredients have reportedly been developed, such gum products often rely on “non-conventional” gum ingredients to achieve desired properties. U.S. Pat. No. 5,882,702, for example, obviates the need for elastomer solvents by replacing elastomers with a plasticized proteinaceous material such as zein. The incorporation of non-conventional ingredients in gum products, however, often compromises taste and thus can be undesirable from a consumer acceptability standpoint.
Moreover, although gum products that allegedly do not stick to teeth and oral prosthetics during mastication are reported (see, e.g., U.S. Pat. No. 4,518,615), there nevertheless remains a need for chewing gum products that also exhibit reduced stickiness or non-stick properties upon disposal of the gum product subsequent to chewing. In particular, there remains a need for environmentally-friendly chewing gum boluses that exhibit either reduced stickiness to, do not stick to, or are rapidly degraded on, those surfaces where gum boluses that are improperly disposed of are often found (e.g., pavement, shoes, hair, undersides of tables and desks).
Additionally, there remains a need for environmentally-friendly chewing gum boluses that are capable of degrading in a short period of time.